ACPICA: Update all ACPICA copyrights and signons to 2010
[linux-2.6.git] / drivers / acpi / acpica / dsmethod.c
1 /******************************************************************************
2  *
3  * Module Name: dsmethod - Parser/Interpreter interface - control method parsing
4  *
5  *****************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2010, Intel Corp.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43
44 #include <acpi/acpi.h>
45 #include "accommon.h"
46 #include "amlcode.h"
47 #include "acdispat.h"
48 #include "acinterp.h"
49 #include "acnamesp.h"
50 #ifdef  ACPI_DISASSEMBLER
51 #include <acpi/acdisasm.h>
52 #endif
53
54 #define _COMPONENT          ACPI_DISPATCHER
55 ACPI_MODULE_NAME("dsmethod")
56
57 /* Local prototypes */
58 static acpi_status
59 acpi_ds_create_method_mutex(union acpi_operand_object *method_desc);
60
61 /*******************************************************************************
62  *
63  * FUNCTION:    acpi_ds_method_error
64  *
65  * PARAMETERS:  Status          - Execution status
66  *              walk_state      - Current state
67  *
68  * RETURN:      Status
69  *
70  * DESCRIPTION: Called on method error. Invoke the global exception handler if
71  *              present, dump the method data if the disassembler is configured
72  *
73  *              Note: Allows the exception handler to change the status code
74  *
75  ******************************************************************************/
76
77 acpi_status
78 acpi_ds_method_error(acpi_status status, struct acpi_walk_state *walk_state)
79 {
80         ACPI_FUNCTION_ENTRY();
81
82         /* Ignore AE_OK and control exception codes */
83
84         if (ACPI_SUCCESS(status) || (status & AE_CODE_CONTROL)) {
85                 return (status);
86         }
87
88         /* Invoke the global exception handler */
89
90         if (acpi_gbl_exception_handler) {
91
92                 /* Exit the interpreter, allow handler to execute methods */
93
94                 acpi_ex_exit_interpreter();
95
96                 /*
97                  * Handler can map the exception code to anything it wants, including
98                  * AE_OK, in which case the executing method will not be aborted.
99                  */
100                 status = acpi_gbl_exception_handler(status,
101                                                     walk_state->method_node ?
102                                                     walk_state->method_node->
103                                                     name.integer : 0,
104                                                     walk_state->opcode,
105                                                     walk_state->aml_offset,
106                                                     NULL);
107                 acpi_ex_enter_interpreter();
108         }
109
110         acpi_ds_clear_implicit_return(walk_state);
111
112 #ifdef ACPI_DISASSEMBLER
113         if (ACPI_FAILURE(status)) {
114
115                 /* Display method locals/args if disassembler is present */
116
117                 acpi_dm_dump_method_info(status, walk_state, walk_state->op);
118         }
119 #endif
120
121         return (status);
122 }
123
124 /*******************************************************************************
125  *
126  * FUNCTION:    acpi_ds_create_method_mutex
127  *
128  * PARAMETERS:  obj_desc            - The method object
129  *
130  * RETURN:      Status
131  *
132  * DESCRIPTION: Create a mutex object for a serialized control method
133  *
134  ******************************************************************************/
135
136 static acpi_status
137 acpi_ds_create_method_mutex(union acpi_operand_object *method_desc)
138 {
139         union acpi_operand_object *mutex_desc;
140         acpi_status status;
141
142         ACPI_FUNCTION_TRACE(ds_create_method_mutex);
143
144         /* Create the new mutex object */
145
146         mutex_desc = acpi_ut_create_internal_object(ACPI_TYPE_MUTEX);
147         if (!mutex_desc) {
148                 return_ACPI_STATUS(AE_NO_MEMORY);
149         }
150
151         /* Create the actual OS Mutex */
152
153         status = acpi_os_create_mutex(&mutex_desc->mutex.os_mutex);
154         if (ACPI_FAILURE(status)) {
155                 return_ACPI_STATUS(status);
156         }
157
158         mutex_desc->mutex.sync_level = method_desc->method.sync_level;
159         method_desc->method.mutex = mutex_desc;
160         return_ACPI_STATUS(AE_OK);
161 }
162
163 /*******************************************************************************
164  *
165  * FUNCTION:    acpi_ds_begin_method_execution
166  *
167  * PARAMETERS:  method_node         - Node of the method
168  *              obj_desc            - The method object
169  *              walk_state          - current state, NULL if not yet executing
170  *                                    a method.
171  *
172  * RETURN:      Status
173  *
174  * DESCRIPTION: Prepare a method for execution.  Parses the method if necessary,
175  *              increments the thread count, and waits at the method semaphore
176  *              for clearance to execute.
177  *
178  ******************************************************************************/
179
180 acpi_status
181 acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
182                                union acpi_operand_object *obj_desc,
183                                struct acpi_walk_state *walk_state)
184 {
185         acpi_status status = AE_OK;
186
187         ACPI_FUNCTION_TRACE_PTR(ds_begin_method_execution, method_node);
188
189         if (!method_node) {
190                 return_ACPI_STATUS(AE_NULL_ENTRY);
191         }
192
193         /* Prevent wraparound of thread count */
194
195         if (obj_desc->method.thread_count == ACPI_UINT8_MAX) {
196                 ACPI_ERROR((AE_INFO,
197                             "Method reached maximum reentrancy limit (255)"));
198                 return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
199         }
200
201         /*
202          * If this method is serialized, we need to acquire the method mutex.
203          */
204         if (obj_desc->method.method_flags & AML_METHOD_SERIALIZED) {
205                 /*
206                  * Create a mutex for the method if it is defined to be Serialized
207                  * and a mutex has not already been created. We defer the mutex creation
208                  * until a method is actually executed, to minimize the object count
209                  */
210                 if (!obj_desc->method.mutex) {
211                         status = acpi_ds_create_method_mutex(obj_desc);
212                         if (ACPI_FAILURE(status)) {
213                                 return_ACPI_STATUS(status);
214                         }
215                 }
216
217                 /*
218                  * The current_sync_level (per-thread) must be less than or equal to
219                  * the sync level of the method. This mechanism provides some
220                  * deadlock prevention
221                  *
222                  * Top-level method invocation has no walk state at this point
223                  */
224                 if (walk_state &&
225                     (walk_state->thread->current_sync_level >
226                      obj_desc->method.mutex->mutex.sync_level)) {
227                         ACPI_ERROR((AE_INFO,
228                                     "Cannot acquire Mutex for method [%4.4s], current SyncLevel is too large (%d)",
229                                     acpi_ut_get_node_name(method_node),
230                                     walk_state->thread->current_sync_level));
231
232                         return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
233                 }
234
235                 /*
236                  * Obtain the method mutex if necessary. Do not acquire mutex for a
237                  * recursive call.
238                  */
239                 if (!walk_state ||
240                     !obj_desc->method.mutex->mutex.thread_id ||
241                     (walk_state->thread->thread_id !=
242                      obj_desc->method.mutex->mutex.thread_id)) {
243                         /*
244                          * Acquire the method mutex. This releases the interpreter if we
245                          * block (and reacquires it before it returns)
246                          */
247                         status =
248                             acpi_ex_system_wait_mutex(obj_desc->method.mutex->
249                                                       mutex.os_mutex,
250                                                       ACPI_WAIT_FOREVER);
251                         if (ACPI_FAILURE(status)) {
252                                 return_ACPI_STATUS(status);
253                         }
254
255                         /* Update the mutex and walk info and save the original sync_level */
256
257                         if (walk_state) {
258                                 obj_desc->method.mutex->mutex.
259                                     original_sync_level =
260                                     walk_state->thread->current_sync_level;
261
262                                 obj_desc->method.mutex->mutex.thread_id =
263                                     walk_state->thread->thread_id;
264                                 walk_state->thread->current_sync_level =
265                                     obj_desc->method.sync_level;
266                         } else {
267                                 obj_desc->method.mutex->mutex.
268                                     original_sync_level =
269                                     obj_desc->method.mutex->mutex.sync_level;
270                         }
271                 }
272
273                 /* Always increase acquisition depth */
274
275                 obj_desc->method.mutex->mutex.acquisition_depth++;
276         }
277
278         /*
279          * Allocate an Owner ID for this method, only if this is the first thread
280          * to begin concurrent execution. We only need one owner_id, even if the
281          * method is invoked recursively.
282          */
283         if (!obj_desc->method.owner_id) {
284                 status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id);
285                 if (ACPI_FAILURE(status)) {
286                         goto cleanup;
287                 }
288         }
289
290         /*
291          * Increment the method parse tree thread count since it has been
292          * reentered one more time (even if it is the same thread)
293          */
294         obj_desc->method.thread_count++;
295         return_ACPI_STATUS(status);
296
297       cleanup:
298         /* On error, must release the method mutex (if present) */
299
300         if (obj_desc->method.mutex) {
301                 acpi_os_release_mutex(obj_desc->method.mutex->mutex.os_mutex);
302         }
303         return_ACPI_STATUS(status);
304 }
305
306 /*******************************************************************************
307  *
308  * FUNCTION:    acpi_ds_call_control_method
309  *
310  * PARAMETERS:  Thread              - Info for this thread
311  *              this_walk_state     - Current walk state
312  *              Op                  - Current Op to be walked
313  *
314  * RETURN:      Status
315  *
316  * DESCRIPTION: Transfer execution to a called control method
317  *
318  ******************************************************************************/
319
320 acpi_status
321 acpi_ds_call_control_method(struct acpi_thread_state *thread,
322                             struct acpi_walk_state *this_walk_state,
323                             union acpi_parse_object *op)
324 {
325         acpi_status status;
326         struct acpi_namespace_node *method_node;
327         struct acpi_walk_state *next_walk_state = NULL;
328         union acpi_operand_object *obj_desc;
329         struct acpi_evaluate_info *info;
330         u32 i;
331
332         ACPI_FUNCTION_TRACE_PTR(ds_call_control_method, this_walk_state);
333
334         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
335                           "Calling method %p, currentstate=%p\n",
336                           this_walk_state->prev_op, this_walk_state));
337
338         /*
339          * Get the namespace entry for the control method we are about to call
340          */
341         method_node = this_walk_state->method_call_node;
342         if (!method_node) {
343                 return_ACPI_STATUS(AE_NULL_ENTRY);
344         }
345
346         obj_desc = acpi_ns_get_attached_object(method_node);
347         if (!obj_desc) {
348                 return_ACPI_STATUS(AE_NULL_OBJECT);
349         }
350
351         /* Init for new method, possibly wait on method mutex */
352
353         status = acpi_ds_begin_method_execution(method_node, obj_desc,
354                                                 this_walk_state);
355         if (ACPI_FAILURE(status)) {
356                 return_ACPI_STATUS(status);
357         }
358
359         /* Begin method parse/execution. Create a new walk state */
360
361         next_walk_state = acpi_ds_create_walk_state(obj_desc->method.owner_id,
362                                                     NULL, obj_desc, thread);
363         if (!next_walk_state) {
364                 status = AE_NO_MEMORY;
365                 goto cleanup;
366         }
367
368         /*
369          * The resolved arguments were put on the previous walk state's operand
370          * stack. Operands on the previous walk state stack always
371          * start at index 0. Also, null terminate the list of arguments
372          */
373         this_walk_state->operands[this_walk_state->num_operands] = NULL;
374
375         /*
376          * Allocate and initialize the evaluation information block
377          * TBD: this is somewhat inefficient, should change interface to
378          * ds_init_aml_walk. For now, keeps this struct off the CPU stack
379          */
380         info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
381         if (!info) {
382                 return_ACPI_STATUS(AE_NO_MEMORY);
383         }
384
385         info->parameters = &this_walk_state->operands[0];
386
387         status = acpi_ds_init_aml_walk(next_walk_state, NULL, method_node,
388                                        obj_desc->method.aml_start,
389                                        obj_desc->method.aml_length, info,
390                                        ACPI_IMODE_EXECUTE);
391
392         ACPI_FREE(info);
393         if (ACPI_FAILURE(status)) {
394                 goto cleanup;
395         }
396
397         /*
398          * Delete the operands on the previous walkstate operand stack
399          * (they were copied to new objects)
400          */
401         for (i = 0; i < obj_desc->method.param_count; i++) {
402                 acpi_ut_remove_reference(this_walk_state->operands[i]);
403                 this_walk_state->operands[i] = NULL;
404         }
405
406         /* Clear the operand stack */
407
408         this_walk_state->num_operands = 0;
409
410         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
411                           "**** Begin nested execution of [%4.4s] **** WalkState=%p\n",
412                           method_node->name.ascii, next_walk_state));
413
414         /* Invoke an internal method if necessary */
415
416         if (obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY) {
417                 status = obj_desc->method.extra.implementation(next_walk_state);
418                 if (status == AE_OK) {
419                         status = AE_CTRL_TERMINATE;
420                 }
421         }
422
423         return_ACPI_STATUS(status);
424
425       cleanup:
426
427         /* On error, we must terminate the method properly */
428
429         acpi_ds_terminate_control_method(obj_desc, next_walk_state);
430         if (next_walk_state) {
431                 acpi_ds_delete_walk_state(next_walk_state);
432         }
433
434         return_ACPI_STATUS(status);
435 }
436
437 /*******************************************************************************
438  *
439  * FUNCTION:    acpi_ds_restart_control_method
440  *
441  * PARAMETERS:  walk_state          - State for preempted method (caller)
442  *              return_desc         - Return value from the called method
443  *
444  * RETURN:      Status
445  *
446  * DESCRIPTION: Restart a method that was preempted by another (nested) method
447  *              invocation.  Handle the return value (if any) from the callee.
448  *
449  ******************************************************************************/
450
451 acpi_status
452 acpi_ds_restart_control_method(struct acpi_walk_state *walk_state,
453                                union acpi_operand_object *return_desc)
454 {
455         acpi_status status;
456         int same_as_implicit_return;
457
458         ACPI_FUNCTION_TRACE_PTR(ds_restart_control_method, walk_state);
459
460         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
461                           "****Restart [%4.4s] Op %p ReturnValueFromCallee %p\n",
462                           acpi_ut_get_node_name(walk_state->method_node),
463                           walk_state->method_call_op, return_desc));
464
465         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
466                           "    ReturnFromThisMethodUsed?=%X ResStack %p Walk %p\n",
467                           walk_state->return_used,
468                           walk_state->results, walk_state));
469
470         /* Did the called method return a value? */
471
472         if (return_desc) {
473
474                 /* Is the implicit return object the same as the return desc? */
475
476                 same_as_implicit_return =
477                     (walk_state->implicit_return_obj == return_desc);
478
479                 /* Are we actually going to use the return value? */
480
481                 if (walk_state->return_used) {
482
483                         /* Save the return value from the previous method */
484
485                         status = acpi_ds_result_push(return_desc, walk_state);
486                         if (ACPI_FAILURE(status)) {
487                                 acpi_ut_remove_reference(return_desc);
488                                 return_ACPI_STATUS(status);
489                         }
490
491                         /*
492                          * Save as THIS method's return value in case it is returned
493                          * immediately to yet another method
494                          */
495                         walk_state->return_desc = return_desc;
496                 }
497
498                 /*
499                  * The following code is the optional support for the so-called
500                  * "implicit return". Some AML code assumes that the last value of the
501                  * method is "implicitly" returned to the caller, in the absence of an
502                  * explicit return value.
503                  *
504                  * Just save the last result of the method as the return value.
505                  *
506                  * NOTE: this is optional because the ASL language does not actually
507                  * support this behavior.
508                  */
509                 else if (!acpi_ds_do_implicit_return
510                          (return_desc, walk_state, FALSE)
511                          || same_as_implicit_return) {
512                         /*
513                          * Delete the return value if it will not be used by the
514                          * calling method or remove one reference if the explicit return
515                          * is the same as the implicit return value.
516                          */
517                         acpi_ut_remove_reference(return_desc);
518                 }
519         }
520
521         return_ACPI_STATUS(AE_OK);
522 }
523
524 /*******************************************************************************
525  *
526  * FUNCTION:    acpi_ds_terminate_control_method
527  *
528  * PARAMETERS:  method_desc         - Method object
529  *              walk_state          - State associated with the method
530  *
531  * RETURN:      None
532  *
533  * DESCRIPTION: Terminate a control method.  Delete everything that the method
534  *              created, delete all locals and arguments, and delete the parse
535  *              tree if requested.
536  *
537  * MUTEX:       Interpreter is locked
538  *
539  ******************************************************************************/
540
541 void
542 acpi_ds_terminate_control_method(union acpi_operand_object *method_desc,
543                                  struct acpi_walk_state *walk_state)
544 {
545
546         ACPI_FUNCTION_TRACE_PTR(ds_terminate_control_method, walk_state);
547
548         /* method_desc is required, walk_state is optional */
549
550         if (!method_desc) {
551                 return_VOID;
552         }
553
554         if (walk_state) {
555
556                 /* Delete all arguments and locals */
557
558                 acpi_ds_method_data_delete_all(walk_state);
559
560                 /*
561                  * If method is serialized, release the mutex and restore the
562                  * current sync level for this thread
563                  */
564                 if (method_desc->method.mutex) {
565
566                         /* Acquisition Depth handles recursive calls */
567
568                         method_desc->method.mutex->mutex.acquisition_depth--;
569                         if (!method_desc->method.mutex->mutex.acquisition_depth) {
570                                 walk_state->thread->current_sync_level =
571                                     method_desc->method.mutex->mutex.
572                                     original_sync_level;
573
574                                 acpi_os_release_mutex(method_desc->method.
575                                                       mutex->mutex.os_mutex);
576                                 method_desc->method.mutex->mutex.thread_id = NULL;
577                         }
578                 }
579
580                 /*
581                  * Delete any namespace objects created anywhere within the
582                  * namespace by the execution of this method. Unless this method
583                  * is a module-level executable code method, in which case we
584                  * want make the objects permanent.
585                  */
586                 if (!(method_desc->method.flags & AOPOBJ_MODULE_LEVEL)) {
587                         acpi_ns_delete_namespace_by_owner(method_desc->method.
588                                                           owner_id);
589                 }
590         }
591
592         /* Decrement the thread count on the method */
593
594         if (method_desc->method.thread_count) {
595                 method_desc->method.thread_count--;
596         } else {
597                 ACPI_ERROR((AE_INFO, "Invalid zero thread count in method"));
598         }
599
600         /* Are there any other threads currently executing this method? */
601
602         if (method_desc->method.thread_count) {
603                 /*
604                  * Additional threads. Do not release the owner_id in this case,
605                  * we immediately reuse it for the next thread executing this method
606                  */
607                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
608                                   "*** Completed execution of one thread, %d threads remaining\n",
609                                   method_desc->method.thread_count));
610         } else {
611                 /* This is the only executing thread for this method */
612
613                 /*
614                  * Support to dynamically change a method from not_serialized to
615                  * Serialized if it appears that the method is incorrectly written and
616                  * does not support multiple thread execution. The best example of this
617                  * is if such a method creates namespace objects and blocks. A second
618                  * thread will fail with an AE_ALREADY_EXISTS exception
619                  *
620                  * This code is here because we must wait until the last thread exits
621                  * before creating the synchronization semaphore.
622                  */
623                 if ((method_desc->method.method_flags & AML_METHOD_SERIALIZED)
624                     && (!method_desc->method.mutex)) {
625                         (void)acpi_ds_create_method_mutex(method_desc);
626                 }
627
628                 /* No more threads, we can free the owner_id */
629
630                 if (!(method_desc->method.flags & AOPOBJ_MODULE_LEVEL)) {
631                         acpi_ut_release_owner_id(&method_desc->method.owner_id);
632                 }
633         }
634
635         return_VOID;
636 }